Summary

Plant cells communicate with one another through plasmodesmata, cytoplasmic bridges that can carry metabolites and proteins. P. Zambryski discusses two papers in this week's issue of Science (pp. 1980 and 1983), which show that plasmodesmata are inherently dynamic, altering their dimensions to increase their transport capability in response to viral or endogenous proteins, and that proteins travel to plasmodesmata on the cytoskeleton.